The present invention relates to a contact drive assembly for use with test equipment for various measurements and tests of semiconductor integrated circuits, that is, electronic parts having at least one terminal pin, such as IC's, LSI's, resistance elements, capacitance elements and so forth. In particular, the present invention pertains to a contact drive assembly which automatically connects the terminal pin of such an electronic part under test with a test equipment measuring circuit.
With a conventional contact drive assembly of this kind, when an electronic part to be measured is placed in a measuring part of measuring equipment, a driver is rotated, by which a movable contact piece connected to the measuring circuit is moved, against the resiliency of the contact piece itself, into contact with a terminal pin of the electronic part. Such a prior art device includes mechanical moving parts and hence is defective in that when it is used for a long time, the mechanical moving parts become worn and loose, so that good contact between the movable contact piece and the terminal cannot be obtained, thereby making it impossible to conduct correct measurements or tests.
To avoid the above defect, there has been employed a method in which compressed air is supplied to a flexible tube to inflate it to press a movable member through the flexible tube and a movable contact piece is urged by the movable member to engage with or disengage from the terminal pin. This method employs less mechanical moving parts and ensures good contact between the movable contact piece and the terminal pin. Also in this case, however, the mechanical moving part of the movable member is involved and it is difficult for the movable contact piece to make good contact with the top end portion of the terminal pin without bending the terminal pin because of the contact piece urging force.